Observations on flight behavior - differentiation of the unequal bark beetle from the black timber bark beetle.

摘要

Studies on the flight behaviour of the unequal bark beetle (Xyleborus dispar) and black timber bark beetle (Xyleborus germanus [Xylosandrus germanus]) were conducted in Karlsruhe-Augustenberg, Germany, during 1996-2002, focusing on the flight habit and population dynamics of the bark beetle species. Due to a false definition, part of the material in the publication "Observations on the Flight Dynamics of Bark Beetle (Xyleborus saxeseni [Xyleborinus saxeseni] and Xyleborus dispar)" [see Gesunde Pflanzen (2003) 3, 53-61] is corrected in this article. The flight of the unequal bark beetle started in spring when the maximum daytime temperature reached 18 degrees C or higher (as a rule, the end of March or first week of April). Their flight continued until the beginning of July. The beetle which we had defined incorrectly as the male of the species was determined to be the black timber bark beetle by an entomologist at the Bavarian Forestry Institute. The flight of this beetle started later, in the last fortnight of April, mostly toward the end of the month. The proportion of unequal bark beetles in alcohol traps varied from 9.1 to 53.3% (27.4% on average), whereas that of the black timber bark beetle varied from 3.3 to 9.5% (5.1% on average).